Vitreous decalcomania



Nov. 7, 1961 L. F. AKKERON 3,007,829

VITREOUS DECALCOMANIA Filed Feb. 9, 1959 HEAT ACT/VA TABLE names/v5 wmsous ass/aw 3 CLEAR LAYER HEAT RELEASE .2? COfiT/NG BARRIER LHYER PAPER BHCKING' 6 HEAT HC'TIVA TABLE 5 M l H 0 HE 5/ v5 wz gg s v 5 HEW RELEASE COHTING PHPER BECK/N6 Patented Nov. 7, 1961 ice 3,007,829 VETEEOUS DECALCDMANEA Ludwig F. Akkeron, Chicago, Ill, assignor to The Meyercord Co, Chicago, 111., a corporation of Illinois Filed Feb. 9, 1959, Ser. No. 792,007 12 Claims. (Cl. 1568) This invention relates to improvements in vitreous decalcomanias or transfers of the type used in the decoration of chinaware, glassware, pottery, porcelain ware and the like.

For many years, comania transfers prepared with special vitrifiable or ceramic colors in the decoration of articles of glassware, chinaware or the like. For example, a water release type decalcornania has been widely used and consists essentially of a paper carrier or backing having the desired design imprinted thereon in one or more vitrifiable enamel colors. The backing paper may be either the slide otf type having a thin layer of a water soluble gum or may be a so-called duplex paper consisting of a layer of thin tissue paper with a water soluble gum coating on one side and releasably adhered at its other side to a heavier paper sheet. In either case, however, soaking with water is necessary to effect release of the transfer design from the backing. After the design has been temporarily adhered to the ceramic article it is necessary to dry the article thoroughly to remove all traces of water after which a high temperature firing operation is employed in the usual manner.

Although vitreous decalcomam'as of the water release type have enjoyed widespread commercial use, it is well recognized that they have serious disadvantages arising primarily from the fact that a number of inconvenient and thne-consuming steps are required. Furthermore, the use of water or varnish and the presence of water soluble gum introduces innumerable difiiculties so that the water release type transfers require considerable care and skill in the use thereof and do not lend themselves to high speed machine application.

In order to overcome these various disadvantages of the water release type vitreous decalcomanias it has been proposed to employ a transfer of the heat release type. In this connection, reference is made to a copending application Serial No. 633,994, filed January 14, 1957, by Frank L. Porth (now US. Patent No. 2,970,076, issued January 31, 1961), the Forth application and the present application being owned by a common assignee. A heat release vitreous decalcoman-ia is characterized by the use of a heat releasable backing at one side of the vitreous design and an outer thermoplastic or heat activatable adhesive at the opposite side of the vitreous design. As a result, when the decalcomania is subjected to heat the vitreous design layer is released from the backing and is also temporarily adhered to the article being decorated, both effects being accomplished in substantially a single step. The present invention is concerned with improvements in a heat release vitreous decalcomania or transfer of the type just described.

In decorating an article of chinaware, glassware, or the like, the article which is quite hot as formed is cooled to a suitable temperature before the application of the decoration and is then reheated to fire the vitreous design. This cooling step is particularly necessary in the case where the article is decorated directly by screen printing or by the use of a water release type transfer as previously described. In such cases, it is generally necessary to cool the article to room temperature prior to decoration. However, even in the case of a heat release transfer where the heat of the article may be relied upon to eifect release of the design from the backing, it has still been necessary heretofore to cool the article to it has been customary to use decala substantial extent in order to achieve success. For example, in the case where a wax or wax-like material is employed as the heat release agent for r-eleasably adhering the vitreous design to the transfer backing, it has been necessary heretofore to adjust the temperautre of the ware so that it is only slightly above the melting point or softening point of the wax. If the temperature of the ware is too high, the heat release materials heretofore known do not function properly and the desired successful release is not always obtained. Moreover, in many instances such as in the decoration of glassware or under-glaze decoration of bisque, it is highly desirable to be able to decorate the ware at relatively higher temperatures in order to eliminate extensive cooling and thereby speed up the overall operation with a resultant sav ing and increased production rate.

Accordingly, a primary object of the present invention is to provide an improved vitreous transfer of the heat release type which is capable of being used at substantially higher ware temperatures than has been possible heretofore.

A further object of the invention is to provide a novel and improved heat release formulation for a vitreous decalcomania of the type described.

Other objects and advantages of the invention will become evident from the subsequent detailed description taken in conjunction with your accompanying drawings wherein:

FIG. 1 is a diagrammatic cross-sectional representation on an exaggerated scale of a decalcomania transfer comprising one specific embodiment of the invention; and

FIG. 2 is a view similar to FIG. 1 but showing a modification of the invention.

Referring first to FIG. 1, the embodiment of the invention therein illustrated comprises a vitreous decalcomania or transfer which is adapted for manufacture by any suitable printing method, e.g. silk screen printing, lithography, rotogravure, or letter press printing. The decalcomania has a releasable backing comprising in this instance a paper sheet 1 with a barrier layer or coating 2 which renders one side of the paper less porous and retards penetration by wax or wax-like materials. As hereinafter described in connection with FIG. 2, the barrier coating 2 may be omitted if desired. The barrier coated paper is also provided with a superimposed coating 3 of a special wax-like heat release material which constitutes the principal feature of the invention, as hereinafter described in detail. A clear resinous film 4 is disposed over the heat release coating 3 and serves as an imprint receiving support for the subsequently applied vitreous design. The vitreous design, indicated at 5, is disposed directly against the clear layer 4, it being understood that the design 5 will usually comprise a compound or composite layer including a plurality of different ceramic color compositions arranged to provide the desired ornamentation or text matter. Over the outermost side of the vitreous design 5 is provided a layer 6 of a suitable thermoplastic or heat activartable adhesive material which serves as a temporary binder for securing the design 5 to the article being decorated.

The vitreous decalcornania described above is employed in decorating a ceramic or glass article by contacting the outermost thermoplastic layer 6 of the transfer with the heated article. The heat thus applied to the transfer accomplishes two effects in a single step. In the first place, the thermoplastic layer '6 is activatedv or rendered tacky so that the vitreous design 5 is temporarily adhered to the ceramic or glass surface. At the same time, the application of heat to the decalcomania from the design side thereof causes the heat release coating 3 to melt or soften thereby automatically releasing the barrier coated paper backing. It will be understood that the clear layer 4 is released as a unit with the design 5 and is disposed outermost when the design 5 is on the article. Thereafter, the article is fired at a high temperature in the usual manner so that the vitreous design 5 is melted and permanently fused into the ceramic or glass surface. The clear layer 4, the organic components of the vitreous design 5, and the temporary adhesive 6 are completely consumed during the firing operation so that only the pigmented flux component of the vitreous design 5 remains. The foregoing decorating technique may be applied either to glazed or unglazed ware. In the case of the latter, the transfer is applied to the bisque or unglazed article. Thereafter the bisque with the temporarily adhered design is heated to dispel the organic components of the design and a liquid glaze is then applied by dipping or spraying. After an initial drying period, the ware is then fired to produce the finished article having a very durable underglazed decoration. Although it is also possible to apply the transfer by placing the design side of the transfer against an unheated article and then applying heat to the backing side of the transfer, the above described technique of preheating the ceramic or glass article before contact with the transfer is found to be highly advantageous because it affords better release of the design from the backing and lends itself very readily to high speed machine application.

As heretofore mentioned, when ceramic or glass articles are first manufactured they are at a very high temperature and must necessarily be cooled substantially before they can be decorated by the usual decorating techniques. 'For example, in the case of glass bottles, as the bottle comes from the glass forming mold it may have a temperature of 1l001200 F. and in order to cool the same to a lower temperature suitable for decoration, the bottle must be passed through an annealing lehr so as to obtain gradual cooling without setting up undue strains in the glass. Obviously, such a prolonged cooling step is a costly and time-consuming operation. Furthermore, after the decoration has been applied, the decorated article must then be reheated and fired and again cooled in an annealing lehr. Accordingly, it will be understood that even when the decoration of the ware is accomplished by means of a heat releasable vitreous decalcomania, it is still desirable to be able to eliminate or at least minimize the extent of cooling necessary prior to decoration.

Although the heat release layer of a heat release type vitreous decalcomania may comprise a vegetable or mineral wax having a melting point within the range of from about 160 F. to about 220 F., such heat release layers are not suitable for application to ceramic ware or glassware at high temperatures. When the temperature of the ware is appreciably higher than the melting point of the wax, it will be found that the wax is dissipated too rapidly to permit proper release of the design layer from the backing. This difliculty is accounted for, at least in part, by the fact that the molten wax at high temperatures has a low viscosity and tends to be absorbed into the paper backing. Furthermore, the reduced viscosity of the molten wax at high temperatures allows the molten wax film literally to be squeezed out or extruded under the pressure of application when the ware is pressed against the decalcomania transfer. In any event, experience has shown that with the usual vegetable or mineral waxes, the temperature of the ware can be only slightly above the softening point of the wax in order for the transfer to be applied successfully. Otherwise, the ceramic colors in the design layer apparently make direct contact with the paper sheet and tend to stick or adhere to the same.

In accordance with the present invention, a special formulation is employed for the heat release layer 3 (FIG. 1) which overcomes the aforementioned difiiculties and permits the transfer to be applied successfully to the Ware while the latter is at a temperature appreciably above the melting point or softening point of the heat release material. For the heat release coating 3 I employ a mixture which is solid at room temperature and comprises a major proportion of one or more normally solid polyethylene glycols and a minor proportion of a normally liquid polyethylene glycol. Polyethylene glycols are polymers formed by the addition of ethylene oxide to ethylene glycol or Water and their general structure may be written as:

H(CH OCH ),,-OH

These compounds are normally liquid when their average molecular weight ranges from about 200- to about 600 and are normally solid when their molecular weight is above about 1000. Such materials are available commercially from a number of sources, e.g. the materials sold by Union Carbide Chemicals Company under the trademark Carbowax.

I have found that the melt viscosity of the polyethylene glycol composition, i.e. the viscosity when in molten form, is apparently the controlling factor in obtaining successful release of the vitreous design from the backing when'the transfer is applied at high temperatures. In accordance with the present invention, the normally solid heat release coating formulation must be so constituted that when the heat release coating is melted at the high temperature of the ware, the molten coating still possesses a relatively high viscosity so that it does not readily penetrate into the paper backing 1 and also is not readily squeezed out or extruded from between backing and the design when the transfer and the ware are pressed together. Although the barrier layer 2 minimizes the opportunity for penetration of the molten coating 3 into the paper backing 1, nevertheless, such protection is not entirely adequate if the transfer is applied at high ware temperatures.

I have found that a normally solid polyethylene glycol formulation containing at least about 25 wt. percent of normally solid polyethylene glycol compounds having an average molecular weight of from about 15,000 to about 20,000 possesses the necessary high viscosity when in molten form. For example, Carbowax Compound 20M having an estimated molecular weight of 15,000 to 20,000 and a melt viscosity at 210 F. of 96,000 centipoises is particularly suited for this purpose. Although the softening point of Carbowax 20M is only about 127.4 F. which is not greatly different from the softening points of other polyethylene glycol compounds having much lower molecular weights, yet its melt viscosity is many times greater than the melt viscosity of the lower molecular weight polyethylene glycol compounds.

Although the use of a high molecular weight polyethylene glycol having a high melt viscosity constitutes the crux of the present invention, it is generally desirable as a practical matter to formulate the heat release coating 3 from a mixture of polyethylene glycol compounds in order to provide more acceptable overall properties. The high molecular weight polyethylene glycols having a molecular weight on the order of 15,000 to 20,000 are somewhat hard and brittle in solid form and in order to impart greater flexibility or plasticity to the heat release coating it will usually be desirable to include in the formulation a major proportion of a lower molecular weight normally solid polyethylene glywl having, for example, an average molecular weight of from about 3,000 to about 8,000. For example, Carbowax Compound 4000 having an average molecular weight of 30004700 and Carbowax Compound 6000 having an average molecular weight of 6000-7500 are particularly useful to modify the properties of the higher molecular weight polyethylene glycol compound such as Carbowax Compound 20M. In addition, it is important to include in the formulation a minor percentage of a normally liquid polyethylene glycol compound in order to impart further flexibility or plasticity to the final coating.

Although the proportions of the various polyethylene glycol ingredients in the total formulation may vary considerably, it is preferred to employ at least about 25 wt. 5 percent polyethylene glycol having an average molecular weight of 15000-20000 and at least about 5 wt. percent of a normally liquid polyethylene glycol compound. As heretofore mentioned, the most suitable formulations are those containing a mixture of normally solid polyethylene glycol compounds having both high and low average molecular weights together with a certain percentage of a normally liquid polyethylene glycol compound. Good results are obtained within the following ranges:

Weight percent Normally solid polyethylene glycol, avg. M.W.

l5,000-20,000 to 50 Normally solid polyethylene glycol, avg. M.W. 3000-8000 Normally liquid polyethylene glycol, avg. M.W. 20

200-600 5 to 10 The softening point of the heat release mixture will generally range from about 180 F. to about 340 F. Regardless of the exact proportions of the different polyethylene glycol ingredients, it is essential that the combined mixture have a high melt viscosity within the operating temperature range. For example, a preferred formulation is as follows:

Weight percent Carbowax 20M (avg. M.W. 11000-20000) 25 Carbowax 4000 (avg. M.W. 3000-2700) 70 Carbowax 400 (avg. M.W. 200600) 5 Viscosity (Centipoises) Temp- Mist 1e Carbowax 4000 When a transfer of the type shown in FIG. 1 and hav- 0 ing a heat release layer 3 of the character just described is employed in the decoration of high temperature ware, e.g. at from about 300 F. to about 500 F., excellent results are obtained without encountering the difiiculties which might normally be expected in high temperature applications. Although I do not wish to be bound by theoretical explanations, it is believed that the high melt viscosity of the formulation, as described above, is responsible for the excellent release qualities of the transfer even at higher than usual Ware temperatures. Apparently, the high melt viscosity of the formulation prevents the molten release material from soaking into the paper backing and from being extruded too rapidly from between the backing and the design imprint. Furthermore the above described formulations do not vaporize as rapidly at high temperatures. A further factor of importance is that the high molecular weight polyethylene glycol compounds, such as Carbowax Compound 20M, are appreciably less hygroscopic than the lower molecular weight polyethylene glycol compounds and consequently the quantity of water or moisture present in the heat release coating is somewhat less than would normally be the case. Accordingly, less difiiculty is experienced with blow holes, blisters, and the like due to the rapidly vaporizing moisture at high temperatures.

The high melt viscosity polyethylene glycol formulations may be applied to the paper backing according to the usual hot melt coating techniques at a coating temperature of from about 200 F. to about 300 F. A suitable coating weight has been found to be from about 0.4 to about 3.0 gins. per sq. in. of surface.

For the sake of completeness, the remaining layers of the decalcomania of PEG. 1 will now be described briefly. The barrier layer 2 may be in the nature of a surface sizing or seal coating such as starch, casein, glue, alkali metal silicate, etc., either with or without a clay type filler. A highly satisfactory barrier layer comprises water glass or other alkali metal silicate having dispersed therein talc, clay or like filler. As previously mentioned, the presence of the barrier coating 2 on the paper 1 tends to prevent excessive penetration and absorption of the coating 3 when the latter becomes soft or molten under heat release conditions. Obviously, the material selected for the barrier layer 2 must be stable and relatively unaffected by the temperatures normally encountered during heat release application of the decalcomania. It has also been found that the presence of the barrier coating 2, which seals the pores of the paper, apparently results in a more uniform and smoother heat release coating 3 with the result that is possible to print designs having relatively fine and delicate details without sacrificing clarity.

By reason of the release layer 3, it Will be understood that the transfer body comprising the layers 4, 5, and 6 is releasable as a unit from the coating 3. The layer 4 which provides a base or support for the vitreous design 5 is an unpigmented clear resinous film which is preferably formed from the same organic medium or vehicle which provides the body portion of the various color layers or prints in the vitreous design 5. More specifically, the film 4 may comprise an ethyl cellulose lacquer or an acrylic resin such as a polymerized acrylic resin or a polymethyl methacrylate resin. The resinous layer 4- may be formed. over the heat release surface 3 using a fluid formulation containing a solvent which preferably has no substantial solvent effect on the coating 3. The formulation should also contain a suitable plasticizer such as a chlorinated diphenyl. Merely by way of example, the following is a typical formulation of a material which may be used to form the clear resinous layer 4:

Parts by wt. Lucite acrylic resin (Du Pont L-46) 1 Aromatic petroleum hydrocarbon solvent 1.3

Chlorinated diphenyl plasticizer (Monsanto Chemical- Company, Aroclor 1262) 1 Another typical formulation for the layer 4 using ethyl cellulose is as follows:

As heretofore mentioned, the vitreous design 5 is usually a composite or compound layer formed by imprinting a plurality of successive ceramic colors over the clear layer 4. When the silk screen method of printing is used, the

first vitrifiable color in the form of a relatively viscous liquid or paste is forced through the screen or stencil and onto the clear layer 4. When this first print is dry, subsequent printings are then similarly applied in predetermined sequence and registration to build up the desired final composite design. These printing pastes or inks consist of (1) a vitrifiable material or flux containing a suitable pigment or coloring material, and (2) a fiowable vehicle or binder in which the pigmented flux is dispersed. The pigmented flux materials are well known to those skilled in the deco-ration of glassware and chinaware and are supplied by ceramic color manufacturers as complete vitrifiable or ceramic colors which are then dispersed in the vehicle or medium by the user in accordance with the requirements of the particular job at hand. As the vehicle or medium for the ceramic colors, lacquers are widely used containing a cellulose ester or ether (such as ethylcellulose, cellulose acetate, or nitrocellulose) in a low vapor pressure organic solvent such as ethylene glycol monobutyl ether (Butyl Cellosolve) to which is added a suitable plasticizer such as castor oil, dibutyl phthalate, or a chlorinated diphenyl. Acrylic resins, such as Du Ponts Lucite, also may be used instead of the cellulosic resins and afford certain advantages in some instances.

The proportion of pigmented flux to Vehicle or organic medium in the vitreous ink or paste which is necessary to give satisfactory color values, firing characteristics and shelf life will depend to a large extent on the specific gravity and other properties of the particular pigmented flux or ceramic color. For example, in many instances a suitable paste formulation can be made by grinding about 2 parts by weight of the pigmented flux or ceramic color with about 1 part by Weight of organic medium. The organic medium is provided with a sufficient quantity of plasticizer to enable the printed film to maintain proper flexibility even though carrying a heavy quantity of pigmented fiux. In other instances, eg. where a color deposit of reduced intensity is desired the relative quantity of pig mented flux may be decreased by combining about two parts by weight of pigmented flux with about three parts by weight of organic medium. In the latter case, the plasticizer content of the organic medium will usually be reduced. For certain applications of the vitreous decalcomania herein described improved firing qualities and avoidance of surface disfiguration may be realized by arranging the respective color layers of the design in a predetermined sequence so that the color print adjacent the clear layer 4 constitutes the hardest or most difiicult-ly fusible layer with each successive color layer thereafter being progressively softer or more readily fusible so that the outermost or uppermost color layer of the decalcornania is the softest or most easily fusible. Generally speaking, the degree of hardness or fusing temperature of the respective ceramic colors can be readily controlled by regulation of the composition and quantity of the flux content of the color.

For purposes of illustration, but not by way of limiting the scope of the invention, typical ceramic color formulae for the vitreous design 5 in FIG. 1 may comprise the following:

(1) A white color layer may have a flux consisting of 62.8% lead oxide or litharge, 17.8% boric oxide, 14.1% silicon dioxide, and 5.3% cadmium oxide (all percentages by weight). To this formula 16% by weight of titanium dioxide is milled in as an opacifier.

(2) A red color layer may include a flux containing 56.0% lead oxide or litharge, 29.8% silicon dioxide, 3.2% boric oxide, 2.1% lithium oxide, 4.1% cadmium oxide, 3.0% titanium dioxide, and 1.8% sodium oxide (all percentages by weight). To this flux formula about 9% by weight of red pigment comprising cadmium sulfoselenide and cadmium oxide is milled in.

(3) In the case of a black color layer the flux formulation may include 78.0% lead oxide or litharge, 10.3% boric oxide, and 11.7% silicon dioxide (all percentages by 8 weight). This formula is combined with about 16% by weight of black pigment composed of a mixture of cobalt, chromium and iron oxides.

Each of the foregoing pigmented fluxes is ground in an organic medium, such as a cellulose ester or ether or an acrylic resin vehicle as hereinbefore described, the proportion of organic medium and its plasticizer content being regulated to provide the desired color and storage and firing characteristics in the finished transfer. The clear resin formulations described heretofore for the layer are highly satisfactory for use with the foregoing ceramic color formulations and may be composited in the proportion of 2 parts by weight of ceramic color to 1 part by weight of clear vehicle.

The thermoplastic or heat activatable adhesive layer 6, which constitutes the temporary bonding agent for effecting preliminary adherence of the vitreous design 5 to the article being decorated, may consist of any suitable thermoplastic resinous adhesive such as a maleic modified or maleate resin, an acrylic resin, a vinyl resin, polyvinyl methyl ether, etc. Excellent results are obtained with a modified ethyl cellulose lacquer residue containing a suitable plasticiaer, such as chlorinated diphenyl, and an ester gum, e.g. the glyceryl, methyl, or ethyl esters of rosin acids. One such product known commercially as Reslac 121 -45 and. manufactured by Reslac Chemicals Inc. of Chicago, Illinois is particularly suitable for forming the layer 6.

In FIG. 2 a modification of the invention is shown which is the same as FIG. 1 with the exception that the barrier layer 2 on the paper backing has been omitted. Dependent upon the temperature of the ware in the use of the transfer and other factors, the use of a high melt viscosity material for the heat release layer 3 will frequently prevent excessive absorption of the molten material in the paper 1 to the extent that a separate barrier layer 2 can be omitted without seriously detracting from the release characteristics of the transfer.

Although the invention has been described with particular reference to certain specific embodiments, it is to be understood that various modifications and equivalents may be resorted to without departing from the scope of the invention as defined in the appended claims.

I claim:

1. In a vitreous decalcomania having a vitreous design layer with a heat releasable backing at one side thereof and a heat activatable adhesive material at the opposite thereof whereby upon application of heat the adhesive material is activated for adhering the design layer to an article and the design layer is simultaneously released from the backing, the improvement which comprises a coating of high melt viscosity material on said backing and interposed between said backing and said design layer, said coating comprising a normally solid mixture of polyethylene glycol compounds including at least one polyethylene glycol compound having an average molecular weight of from about 15,000 to about 20,000.

2. The decalcomania of claim 1 further characterized in that said coating has a softening point within the range of from about F. to about 340 F.

3. The decalcomania of claim 1 further characterized in that said coating comprises at least about 25 wt. percent of a polyethylene glycol compound having an average molecular weight of from about 15,000 to about 20,000.

4. The decalcomania of claim 1 further characterized in that said coating comprises at least one polyethylene glycol compound having an average molecular weight of from about 15,000 to about 20,000 and at least one polyethylene glycol compound having an average molecular weight of from about 3000 to about 8000.

5. In a vitreous decalcomania having a vitreous design layer with a heat releasable backing at one side thereof and a heat activatable adhesive material at the opposite thereof whereby upon application of heat the adhesive material is activated for adhering the design layer to an article and the design layer is simultaneously released from the backing, the improvement which comprises a coating of high melt viscosity material on said backing and interposed between said backing and said design layer, said coating comprising a mixture of normally solid polyethylene glycol compounds, at least one of which has an average molecular weight of from about 15,000 to about 20,000, and a normally liquid polyethylene glycol compound.

6. The decalcomania of claim further characterized in that said mixture contains at least about 25 wt. percent of said polyethylene glycol compound having an average molecular weight of from about 15,000 to about 20,000 and at least about 5 Wt. percent of said normally liquid polyethylene glycol compound.

7. In a vitreous decalcomania having a vitreous design layer with a heat releasable backing at one side thereof and a heat activatable adhesive material at the opposite thereof whereby upon application of heat the adhesive material is activated for adhering the design layer to an article and the design layer is simultaneously released from the backing, the improvement which comprises a coating of high melt viscosity material on said backing and interposed between said backing and said design layer, said coating comprising a mixture of normally solid polyethylene glycol compounds, at least one of which has an average molecular weight of from about 15,000 to about 20,000 and at least another of which has an average molecular weight of from about 3000 to about 8000, and a normally liquid polyethylene glycol compound having an average molecular weight of from about 200 to about 600.

8. The decalcomania of claim 7 further characterized in that said mixture contains at least about 25 wt. percent of said polyethylene glycol compound having an average molecular Weight of from about 15,000 to about 20,000 and at least about 5 wt. percent of said normally liquid polyethylene glycol compound.

9. In a vitreous decalcomania having a vitreous design layer with a heat releasable backing at one side thereof and a heat activatable adhesive material at the opposite thereof whereby upon application of heat the adhesive material is activated for adhering the design layer to an article and the design layer is simultaneously released from the backing, the improvement which comprises a coating of high melt viscosity material on said backing and interposed between said backing and said design layer, said coating comprising a normally solid mixture of from about 25 wt. percent to about 50 wt. percent of a polyethylene glycol compound having an average mo- 10 lecular weight of from about 15,000 to about 20,000, from about 40 wt. percent to about wt. percent of a polyethylene glycol compound having an average molecular weight of from about 3000 to about 8000, and from about 5 wt. percent to about 10 wt. percent of a normally liquid polyethylene glycol compound having an average molecular Weight of from about 200 to about 600.

10. The decalcomania of claim 9 further characterized in that said coating has a softening point within the range of from about F. to about 340 F.

11. In a vitreous decalcomania having a vitreous design layer with a heat releasable backing at one side thereof and a heat activatable adhesive material at the opposite thereof whereby upon application of heat the adhesive material is activated for adhering the design layer to an article and the design layer is simultaneously released from the backing, the improvement which comprises a coating of high melt viscosity material on said backing and interposed between said backing and said design layer, said coating comprising a normally solid mixture of about 25 wt. percent of a normally solid polyethylene glycol compound having an average molecular weight of from about 15,000 to about 20,000, about 70 wt. percent of a normally solid polyethylene glycol compound having an average molecular weight of from about 3000 to about 3700, and about 5 wt. percent of a normally liquid polyethylene glycol compound having an average molecular weig t of from about 200 to about 600.

12. In the method of decorating an article of glassware, chinaware, or the like by contacting the article at an elevated temperature with a heat activatable outer surface of a vitreous design layer mounted on a heat releasable backing and thereafter firing the article for permanently fusing the vitreous design to the surface of the article, the improvement which comprises contacting the article while at a temperature of from about 300 F. to about 500 F. with a vitreous desgn layer having a heat activatable outer surface, said vitreous design layer being carried on a temporary backing having a high melt viscosity coating interposed between the backing and the design layer and comprising a normally solid mixture of polyethylene glycol compounds including at least one polyethylene glycol compound having an average molecular weight of from about 15,000 to about 20,000.

July 27, 1954 Jan. 25, 1955 Oughton Townsend UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3.0073329 Ludwig F. Akkeron It is hereby certified that error appears in :bhe above numbered patentrequiring correction and that the said Letters Patent should read as corrected below.

Column 7, line 6 after "design" insert 5 e-q; column 10 line lo for "100 F read W 180 Fa Signed and sealed this 10th day of April 1962.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents November T 1961 

12. IN THE METHOD OF DECORATING AN ARTICLE OF GLASSWARE, CHINAWARE, OR THE LIKE BY CONTACTING THE ARTICLE AT AN ELEVATED TEMPERATURE WITH A HEAT ACTIVATABLE OUTER SURFACE OF A VITREOUS DESIGN LAYER MOUNTED ON A HEAT RELEASABLE BACKING AND THEREAFTER FIRING THE ARTICLE FOR PERMANENTLY FUSING THE VITREOUS DESIGN TO THE SURFACE OF THE ARTICLE, THE IMPROVEMENT WHICH COMPRISES CONTACTING THE ARTICLE WHILE AT A TEMPERATURE OF FROM ABOUT 300* F. TO ABOUT 500*F. WITH A VITREOUS DESIGN LAYER HAVING A HEAT ACTIVATABLE OUTER SURFACE, SAID VITREOUS DESIGN LAYER BEING CARRIED ON A TEMPORARY BACKING HAVING A HIGH MELT VISCOSITY COATING INTERPOSED BETWEEN THE BACKING MIXTURE OF POLYETHYLENE GLYCOL COMPOUNDS INCLUDING AT LEAST ONE POLYETHYLENE GLYCOL COMPOUND HAVING AN AVERAGE MOLECULAR WEIGHT OF FROM ABOUT 15,000 TO ABOUT 20,000. 